4906M09800 Wiseco +3mm Piston Kit for Yamaha YFZ450 YFZ450R 2004-2024 98mm 12.5:

Wiseco +3mm Piston Kit for Yamaha YFZ450/YFZ450R

This Wiseco +3mm piston kit for Yamaha YFZ450 and YFZ450R models is a 98mm forged piston assembly rated at 12.5:1 compression, carrying the Wiseco reference 4906M09800 for a big bore rebuild.

Overview

This Wiseco +3mm piston kit for Yamaha YFZ450 and YFZ450R quads delivers a 98mm forged piston with a 12.5:1 compression ratio for riders rebuilding a worn or tired top end. The kit is built for owners of 2004 through 2024 YFZ450 and YFZ450R models who want a stronger, higher compression piston kit for their machine. Each Wiseco piston kit is made to the 4906M09800 spec so your big bore build stays matched to the correct bore and ratio.

Built For Performance

• 98mm bore size with a +3mm oversize over stock for increased displacement
• 12.5:1 compression ratio suited to high performance four stroke quads
• Forged piston construction for strength under high rpm and heat
• Wiseco reference 4906M09800 identifies the exact piston kit
• Piston kit sized for Yamaha YFZ450 and YFZ450R top end rebuilds

Fits These Machines

• for Yamaha YFZ450
• for Yamaha YFZ450R

On-The-Job Use

• Top end rebuilds after piston wear or loss of compression
• Big bore builds for more displacement and stronger power delivery
• MX and trail riding on YFZ450 and YFZ450R quads
• Refreshing a high hour engine during a full teardown

Specs At A Glance

Good To Know

Q: Does a +3mm piston require boring the cylinder? A: Yes, a 98mm piston needs the cylinder bored and honed to match, so check your current bore before ordering.

Q: Is this a complete top end kit? A: It is a piston kit, so verify the listing contents for rings, pin, and clips, and confirm compression ratio suits your build and fuel.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.